A. Field of Invention
This invention relates to a thin lawn mower blade. More specifically, the invention is a lawn mower blade having a maximum height to blade thickness ratio of at least two-to-one.
B. Description of the Related Art
Lawn mower blades typically have a thickness ranging from 0.150 to 0.250 inches. Known lawn mower blades generally have maximum blade height to blade thickness ratios of approximately one-to-one or just slightly larger. Similarly, bossed sections are usually not integrated into blade designs, but if they are, they are typically very small. Typical manufacture includes the steps of placing a piece of steel or other suitable material in a machine and then stamping it to arrive at the desired shape. After the blade is shaped, heat treatment is performed to increase the strength and durability of the blade.
While current mower blade designs are suitable for their intended purposes, many improvements could be made. For example due to typical blade thickness and corresponding blade weight, the amount of power needed to accelerate and stop the blade is greater than if the blade were not as heavy. Further, damage may occur to mower blades from shock caused by impacting certain obstacles. If the heat-treated lawn mower blade encounters sandy conditions, such as but not limited to those found in coastal regions, then the blades suffer significant wear and tear because the sand impacts the mower components with such force that xe2x80x9csand-blastingxe2x80x9d may occur. Thus, the integrity of the mower blade may decrease over time in sandy conditions.
U.S. Pat. No. 5,775,078 to Warren discloses a mower blade having a blade thickness of 0.25 inches. The maximum height of the blade profile is 0.375 inches. This results in a maximum height to blade thickness ratio of about 1.5. This blade however, does not solve the problem, as does the present invention.
Therefore, there is a need in the art to provide a thin lawn mower blade, which has a maximum height to thickness ratio of at least two to one. It is also desirable to provide a lawn mower blade that is capable of accelerating and stopping quickly and is resistant to various shocks it may encounter, including without limitation, sand. Thus, the current invention provides that the difficulties inherent in thee art are overcome in a way that is simple and efficient, while providing better and more advantageous results.
The present inventive mower blade comprises a main body portion as well as first and second end portions substantially equidistant from the center of rotation, where each of the first and second end portions has a cutting edge portion. Further, the mower blade comprises a maximum height, usually located about the center of rotation. The maximum height to thickness ratio is at least two-to-one.
Accordingly, it is an object of the present invention to provide a mower blade that has a raised center and a high elevational profile, such that a cavity is defined thereunder.
Another object of the present invention is to provide a mower blade comprising a pair of oppositely disposed flange portions operatively connected to the end portions opposite of the cutting edge portion. Each flange portion extends upwardly from each respective end portion, such that airflow properly positions the associated underlying vegetation to be cut.
Still yet another object of the present invention is to provide a lawn mower blade having a maximum height located at the center of rotation.
Further, another object of the present invention is to provide a lawn mower blade having a maximum height-to-blade thickness ratio of at least ten-to-one.
Further, another object of the present invention is to provide a lawn mower blade having a maximum height-to-blade thickness ratio of about least sixteen-to-one.
Another object of the present invention provides a lawn mower blade having a longitudinal axis and a raised center portion, wherein said raised center portion extends about the longitudinal axis, such that the total length of the lawn mower blade is greater than the length of the raised center portion.
Another object of the present invention is to provide a lawn mower blade wherein the high elevational profile increases at an angle as the first and second end portions approach a plateau portion of the raised center portion.
Still yet, another object of the present invention is to provide a lawn mower blade having a raised center portion with a width, wherein, the width is greatest about a transverse axis of the blade. The transverse axis intersects the center of rotation and the width gradually decreases as the raised center portion extends past the plateau portion and towards the first and second end portions.
Still another object of the present in invention is to provide a lawn mower blade having a blade width, wherein the raised center portion width is less than the blade width.
Still yet, another objective of the present invention is to provide a lawn mower blade made of a non-heat treated material.
Another objective of the present invention is to provide a lawn mower blade that has a higher yield strength at the cutting edge portion than the raised center portion, first and second end portions and said flange portions.
Another object of the present invention is to provide a lawn mower blade that is light-weight and that accelerates and stops with less force than known blades.
Still yet, another object of the present invention is to provide a lawn mower blade that absorbs energy on impact.
Yet another object of the present invention is to provide a lawn mower blade that is easy and economical to manufacture.